Research On The Minimum Amount Of Load Shedding For System Which Includes Run Off Small Hydro Power System With Robust Linear Optimization

Most of the Run-off small hydropower has no capacity, poor adjustment ability and its output size are determined by natural inflow.This brings the frequent starting and stopping of the unit and big changes to system operates.Therefore, the research on the minimum amount of load shedding for system which includes Run-off small hydropower system has important implications for the proper planning of the development of the grid which have uncertainties.This article describes the state of the researches and the development of small hydropower in domestic and foreign.Focuses on the advantages and disadvantages for various probabilistic class method which can deal with the problem of random uncertainty. Introducing a robust linear optimization method which use a cassette collection,a ellipsoid formula collection and method based on random variable distribution information deal with the randomness of the problem of uncertainty separately. Duality theory also be introduced to simplify the model. According to the advantages of robust linear optimization method which is without prior known probability distribution function of the amount of uncertainty, putting the output of the run-of small hydropower as a random variable, and using a cassette collection to described the uncertain output characteristics of the run-of small hydropower. Under the same conditions, using the random variable distribution information to described the uncertain output characteristics of the run-of small hydropower again. Then the above uncertainty be converted to determining. Then creating a minimal load shedding model of the run-of small hydropower which is under the constraints of system operation. To make the model easy to solve, duality theory will be used to put the above model into the general linear programming model.By accessing the run-of small hydropower into a 46-node system.Using this two different methods of robust linear optimization,one method is to deal with random variables with a cassette collection;another method is to deal with random variables with random variable distribution information.Getting conclusion by simulating.The former results of simulation show that, the run-off small hydropower systems has significantly affected on the minimum load-shedding of system. After For the run-of small hydropower systems accessed to system,different the disturbance of range of estimates of the output and its different accessing location will cause the changes on the minimum load-shedding amount of the whole network. Two different schemes are set in the last simulation process.Option One shows that different ways of handling uncertainty parameters will cause the changes on the minimum load-shedding amount of the whole network.The model can not only get the most secure scheme of load-shedding, but also get a number of load-shedding scheme between economy and high reliability,and network planning problem can be implemented in a flexible decision-making.Option II shows that separate changes of the accessing capacity of a node in the system will cause the changes on the minimum load-shedding amount of the whole network;but when perturbation is small, the changes of the capacitance value of the accessing node will do not cause the changes on the minimum load-shedding amount of the whole network.Using robust linear optimization theory can effectively measure the reliability of different load-shedding schemes of power system planning programs.